Hearing aids serve primarily to enable patients with hearing impairment to achieve as natural a perception of sound as possible and, to that end, generally to compensate for medically-based functional disturbances of the organs of hearing. It is intended that this should be brought about as conveniently as possible and without appreciable disadvantage to the hearing aid wearer. Accordingly, the functional spectrum of hearing aids includes simple sound pressure amplifying devices and/or prosthetic devices for prosthetic support of stimulus generation in the interior of the ear. Regardless of the embodiment, the hearing aid used will always have the function of converting incident sound pressure into auditory stimuli for the hearing aid wearer like those that would also occur with physiologically and anatomically intact hearing organs. In order to meet these requirements, numerous subjective factors relating to the individual hearing aid wearer which can result from the individual quality of his/her hearing impairment and also the selectivity of his/her perception must be taken into account.
Modern hearing aids therefore allow a plurality of parameters which influence the response and amplification characteristics of the hearing aid used to be adjusted. The adjustment of these parameters usually takes place during manufacturing in the form of a basic setting, which can subsequently be adapted to the patient in the form of fine tuning during one or more sessions with a hearing aid acoustician. It is self-evident that fine tuning of this type is associated with a substantial degree of effort on the part of the patient and the hearing aid acoustician involved and that it can mean a substantial loss of convenience, at least for the patient.
The problem addressed applies to a particularly large extent when the individually adjustable parameters simultaneously form the input variables of complex signal processing algorithms which, in turn, influence the response and amplification characteristics of the hearing aid used. In modern hearing aids, several such algorithms, for example, for suppressing noise and for accentuating desired signal sources are implicit. Examples are (adaptive) directional microphones, algorithms for damping non-speech components, for rapid spectral noise estimation/Wiener filtering, for wind noise suppression or signal envelope-based suppression of transient noise, to name only a few. The potential efficiency of these algorithms is usually adjustable by means of various parameters, although the actual effect depends, apart from this parameterizing, also on the incident sound input signal and the hearing situation represented thereby. The parameterizing of various noise reduction algorithms has also previously been undertaken statically when the hearing aid was adjusted by a hearing aid acoustician. Starting from a presetting undertaken by the manufacturer, this involves the making of manual settings adjustments by the acoustician. Fine tuning of this type can be undertaken in several steps and is also relatively complex. Furthermore, the decision as to which parameters are to be adapted to which algorithm is very difficult to make under laboratory conditions, since the subjective requirements of the hearing aid wearer only become apparent in real auditory situations.
Various possibilities for being able to undertake at least part of the adjustment and/or fine tuning of the hearing aid independently of a hearing aid acoustician are known and, in the ideal case, this is carried out by the hearing aid wearer/patient himself. This type of subsequent adaptation of a hearing aid at any time is possible only to a limited extent. On the one hand, the adjustability of relevant parameters must be prepared technically, which frequently requires an acoustics laboratory, at least in the conception phase and can only be performed under simulated conditions. On the other hand good adaptation to actual auditory situations, particularly with high convenience hearing aids, is partly associated with the adaptation of numerous technical parameters, which can either involve a long-winded search for optimum parameters and/or possibly overstretch the technical knowledge of lay persons, particularly as far as the selection of the relevant parameters and/or algorithms in a given auditory situation is concerned.
It is known to reduce the effort required for external adjustment/fine tuning of a hearing aid in that a real auditory situation is classified, and this enables subsequent allocation of the classified auditory situation to a plurality of saved data records with preset parameters. In this case, it is only the selection of the set of parameters which best match the respective auditory situation that is carried out interactively (EP 0 814 634 B1). However, this procedure requires the storage of a relatively large number of data sets with preset parameters in order to be able to make a finely stepped selection of the suitable parameter set.
It is also known, based on stored preset parameters and the classification of a particular auditory situation, to offer parameter sets which are automatically varied once they have been selected by the hearing aid wearer (EP 1 453 356 A2). However, with automated parameter variation to be defined in advance, it is difficult to undertake optimum adaptation to auditory situations which cannot be predicted in advance if no suitable parameter set is available and/or no suitable parameter variation has been prepared.
It is also known to group together sequences of program steps that are required for adapting a hearing aid to particular auditory situations into macros in order to facilitate their repetition (DE 101 52 197 A1). However, the problem of possible high complexity on first performance of the relevant program steps remains in place.
It is also known, starting from stored preset parameters and the classification of a particular auditory situation, to offer parameter sets which are varied by the hearing aid wearer and then stored and allocated to the classified auditory situation (DE 102005 009 530 B3). The complexity of the parameter variation that has to be carried out remains in hearing aids of this type, however.
It is also known from DE 100 64 210 A1, in order to adapt a hearing aid, to read an electrical input signal from the hearing aid and to feed it to a processor unit for graphical representation. By this means, the effect of a change in hearing aid parameters can be displayed.